Manufacture of shoes



Sept. 26, 1939. H. c. KING 2,173,967

MANUFACTURE OF SHOES Filed Jan. 13, 1936 2 Sheets-Sheet 1 Sept. 26,1939. H. C. KING 2,113 967 MANUFACTURE OF SHOES Filed Jan. 13, 1936 2 Sheets-Sheet 2 Patented Sept. 26, 1939 UNITED STATES amass-r MANUFACTURE OF SHOES Harry 0. King,

Quincy, Mass, assignor to United Shoe Machinery Corporation, Paterson,

N. 1., a corporation of New Jersey Application January 13, 1936, Serial No. 58,886

11 Claims.

This invention relates to improvements in shoes and methods in making the same.

It is customary to stiffen the shank portions of the bottoms of shoes by the use of shank stiifeners made of metal or wood. Such shank stiifeners may be practically rigid or they may have a certain amount of resiliency but invariably they are sufliciently stiff to interfere more or less seriously with the natural flexing of the muscles of the foot. Such stiifeners are supplied in dif-.

ferent lengths aand different bends" for use in connection with lasts of difierent sizes and styles but for one reason or another the shank stiffener is liable to impart to the shoe bottom a contour which falls to conform accurately to the contour of the last bottom and which for that reason is not adapted to afford proper support for the foot. Moreover, considerable difficulty is often experienced in attaching shank stiffeners of wood or metalso that they will remain firmly secured in place throughout the life of the shoe.

For the purpose of avoiding such difliculties as those-abovementioned I employ shank stiffening a means which is more flexible and resilient than either wood or metal of the sort commonly used in making shank stiffeners, which is light in weight, which is capable of being secured in place without the use of such fastening devices as tacks, staples, stitches or the like and which is adapted to be molded to the contour of the bottom of the particular last or the shoe in which the shank stiffener is to be used. I have found that colloid-treated fabric, for example, fabric treated with nitrocellulose, is particularly suitable for use in stiffening the shank portions of shoe bottoms. In making use of a shank stiffener made of such fabric I render the stiffener sticky so that it will adhere readily to the shoe parts 49 with which it is to come in contact and at the same time render it capable of being readily molded into conformity with the shape of a last bottom by applying to it a suitable solvent such as acetone. Thereafter the shank stiffener is made to adhere to the shoe bottom parts and preferably the pressure is applied by means of mold members one of which at least is shaped to correspond to the shape of a last bottom so that the shank stiffener and the adjacent shoe bottom parts will be molded to flt the last bottom. As herein illustrated the shank stiffening means may be secured to an insole member before the insole member is assembled with an upper on a last thereby providing a'reinforced insole or insole unit. In making such a reinforced insole or insole unit the shank stiffener may advantageously be shaped in edge contour to correspond to that of the heel and shank portions of the insole and preferably the shank stiifener is interposed between the insole 5 anda heel and shank reinforcing piece which may be made, for example, from fiber or leatherboard and is preferably also shaped to cbrre spond to the edge contour of the shank stifiener and the heel and shank portion of the insole. 10 Thus, after the parts have been assembled and secured together under molding pressure, a shoe bottom unit is produced comprising an insole member and reinforcing piece for the heel and shank portions of the insole member and a resilient shank stiffener which is interposed between these parts and is permanently secured to both of them by means of adhesive produced by the action of the solvent upon the colloidal element of the shank stiffener. Alternatively, 20 the shank stiffening means may be applied between the inner and outer soles of the shoe, in which case the molding pressure will result in firmly securing the shank stiffener to both the soles, Advantageously, the shank stiffening means may comprise two or more shank stiffening members composed of such material as colloid-treated fabric, one of said members being interposed between the insole and a heel and shank reinforcing piece and the other of said members being interposed between the reinforcing piece and the outsole.

The invention will now be explained with reference to the accompanying drawings, in 35 which- Fig. 1 is a perspective view of the component parts of a shoe bottom unit comprising an insole; a shank stiffener, and a heel and shank reinforcing piece; 0

Fig. 2 is a perspective view of a shank stiffener of a different form from that shown in Fig. 1; Fig. 3 is a fragmentary view, partially in side elevation and partially in section, of a shoe bottom unit in course of construction, illustrating 5 a convenient manner of applying the attaching and molding pressure;

Fig. 4 is. a cross-sectional view of the shoe bottom unit, the section being taken along the line IVIV of Fig. 3 and showing thev unit as 5 it appears after the lateral edges of its 'shank portion have been beveled;

Fig. 5 is a perspective view of the shoe bottom unit a Fig. 6 is a cross-sectional view of'a shoe in course of construction and embody y improved shoe bottom unit; 7

Fig. 7 is a longitudinal sectional view of a shoe having an improved shoe bottom unit embodied therein;

Fig. 8 is a cross-sectional view of the shoe shown in Fig. 7; and

Fig. 9 is a cross-sectional view of a shoe illustrating the modified form of shank stiffening means.

Referring first to Fig. 1, l2 designates a full length insole, il a shank stiifener composed of a colloid-treated fabric and having an edge contour corresponding to that of the heel and shank portions of the insole, and I a heel and shank reinforcing piece composed of fiber or similar material, the reinforcing piece II also having an edge contour corresponding to that of the insole. I prefer to employ a shank stiffener composed of a treated fabric, such as that disclosed in United Sttaes Letters Patent No. 1,820,- 198, granted August 25, 1931, upon application of A. F. Randolph.

In making my improved shoe bottom unit a solvent, for example denatured alcohol and acetone, is applied to the shankstiffener ll, as by means of a brush or by dipping the stiffener in the solvent, and the several parts of the unit are assembled in the relation indicated in Fig. 1, the stiffener [4 being interposed between the insole I2 and the reinforcing piece I. The shank stiffener l4 having been softened and rendered sticky by means of the adhesive produced by the action of the solvent upon the colloidal element of the stiffener, the several parts are firmly secured together by means of. pressure which, as illustrated in Fig. 3, may advantageously be applied by means of mold members comprising a rigid lower form l8 and a yielding upper pad 29. As shown, the insole-engaging surface of the form I8 is made to correspond with that of the bottom of a lastso that when the mold and the form are brought together under pressure not only will the component parts of the bottom unit become firmly secured together but they will also be molded so as to conform to the shape of the bottom of the last. As shown, the form ll may rest upon a support 22 and the pad 29 may be mounted upon a carrier 24 which is movable toward and from the support 22, the form and the pad, together with the means for supporting and relatively moving them, being preferably similar to corresponding means illustrated and described in United States LettersPatent No. 2,065,465, granted December 22, 1936, upon application of John M. Whelton. After the pressure supplied by the pad 2| has been maintained for a suflicient period properly to mold the shoe bottom members and firmly to secure them to gether and preferably also to allow the softened colloidal material to become hardened, the pressure is relieved and a molded shoe bottom member 26, such as that shown in Fig. 5, is produced. Advantageously, the opposite lateral edges of the shank or of the shank and heel portions of the unit may then be beveled, as indicated at 28 in Fig. i, the better to adapt the unit for use in a through the insole l2.

(Fig. 6), the latter preferably being of a type which will penetrate the reinforcing piece I without entering or at least without extending A shank stiffener 36, formed of a colloid-treated fabric, and of a shape corresponding to that of the stiffener Ill, is;

applied to the outer surface of the insole in the space between the overlasted margins of the upper, the shank stiffener 36 having been softened by means of a solvent so that it will readily adhere to the insole and also to the outsole'when the latter has been applied. The shoe is completed by laying an outsole 38 and securing it to the shoebottom by such means as cement or through-and-through stitches.

In case it is not desired to employ a shoe bottom unit such as the unit 28 as the insole of a shoe which is to embody a resilient shank stiffener of moldable and adhesive producing material, the shoe may be made with an ordinary insole (II, as indicated in Fig. 9, and a resilient shank stiffener 360 of adhesive or cement producing material employed between the insole and the outsole, the shank stiffener being softened to render it sticky and moldable, either before or after it has been laid in place upon the shoe bottom. Thereafter the outsole may be laid in the usual way or it may be permanently attached by cementby the use of a cement sole-attaching press in a well-known manner. The shank stiff- .ener will be secured to the inner and outer soles by the sole laying or sole-attaching pressure which will also mold the shank stiffener to the curvature of the adjacent portions of the shoe bottom. As shown in Fig. 9, the outsole, the insole, and the upper materials may be secured together by through-and-through stitching 42.

In the use of my improved shoe or shoe bottom unit it will be found that the shank portion of the shoe or unit, because of the inherent resiliency of the shank stiffening material, will yield readily to accommodate the natural movements of the bones and muscles of the foot in walking but will react promply when the foot pressure is relieved so as to restore the shoe bottom parts to their original and normal shape.

Thus, the foot is enabled to flex and relax in a natural manner and receives such exercise as is essential in order to maintain or restore proper foot posture and to provide for natural and adequate support of the various arches of the foot. Because of the character of the material with which the shank stiffening means is composed and the herein-described manner of treating and applying the stiffening means, the latter not only becomes firmly secured in place without the use of any of .the usual fastening devices but the colloidal element of the stifiening meanspenetratesmore or'less into the adjacent shoe materials, impregnating the latter with a resilient stiffening substance and fusing the several shoe parts together into a practically coherent structure and imparting 'a certain amount of resiliency to the adjacent shoe bottom and upper materials. 7

Moreover, as a result of the molding of the shoe bottom while the shank stiffening means is in a softened or semi-plastic and adhesive state, the stiffening means as well as the rest of the shoe bottom is accurately molded to conform to the 1 contour of the bottom of the last and when the softened shank stiffening means becomes hardened or set it serves to maintain the shoe bottom in the desired foot conforming shape throughout the life of the shoe.

The above-described improvements in methods of making insole units together with certain features of construction of 'my improved insole unit are not claimed herein, the same being disclosed and claimed in a divisional application, Serial No. 228,979, filed September 8, 1938.

Having described my invention, what I claim as new and desire to secure by Letters Patent of the United States is:

1. That improvement in methods of making shoes which comprises lasting an upper over an insole on a last, applying to the shank portion of said insole a stiffening means which consists ened, laying an outsole and thereby conforming said material to the bottom contour of the last,

and maintaining the sole laying pressure during the hardening of the element thereby molding the soles to the form and causing the element t adhere to both soles.

3. That improvement in methods of making shoes which consists in providing shank stiffening means consisting only of a softened strip of colloid-treated fabric between the shank portions of the inner and outer soles of a shoe on a last,

and holding the soles under pressure against the last during the hardening of said treated fabric thereby molding the soles to the shape of the last and causing said fabric to adhere to both soles and to maintain the soles resiliently in their molded forms.

4. That improvement in methods of making shoes which involves interposing between the inner and outer soles of a shoe on a last shank stiflening means consisting only of fabric having associated therewith a substance partially converted into cement by the action of a solvent thereon. and applying molding pressure to the soles thereby molding them and said stiffening means to the shape of the last and securing the stiffener to both soles by means of said cement.

5. That improvement in methods of making shoes which comprises lasting an upper over an insole on a last, applying to the shank portion of the insole a strip of material comprising a base, which of itself is readily flexible and impregnated throughout with a stiffening substance capable of being reduced to a soft sticky state when acted upon by a solvent, applying solvent to the strip, laying an outsole and thereby conforming the softened strip to the bottom contour of the last, and maintaining the sole laying pressure until said strip has become hard and has secured the insole to the outsole.

70 6. That improvement in methods of making shoes which consists in placing an insole on a last, applying to the shank portion of an insole a softened strip of colloid-treated fabric, laying a heel and shank reinforcing piece uponsaid msole over the said strip, lasting an upper over said insole and said heel and shank reinforcing piece, applying to the upper side of said reinforcing piece a softened strip of colloid-treated fabric, and laying an outsole, thereby shaping said soles and both said strips to the bottom contour of the last and adhesively securing said strips to those parts with which they are in contact.

7. That improvement in methods of making shoes which consists in assembling with an upper on a last an insole unit comprising an insole, a shank reinforcing piece and a resilient shank stiifener interposed between the insole and said reinforcing piece and secured to both of said parts by means of cement, working the upper over the last and securing its margin in overlasted position upon said insole unit, forming a shank stiffening member of normally resilient material capable of becoming sticky when softened, softening said member sufiiciently to render its onposite sides sticky and introducing it between the overlasted margins of the upper in the shank portion of the shoe bottom, laying an outsole thereby causing said shank stiffener to adhere to said insole unit and to said outsole, and attaching the marginal portions of the outsole to'the overlasted upper.

8. In a shoe, an insole, an outsole, a shank reinforcing piece interposed between said soles, a resilient shank stifl'ener strip interposed between the insole and said reinforcing piece, and a second shank stiffener strip interposed between said reinforcing piece and the outsole, said stiflener strips being impregnated with an adhesive stiffening medium and each being permanently secured by said medium to the adjacent shoe bottom parts.

9. In a shoe, an insole, an outsole, a heel and shank reinforcing piece between said soles, a resilient shank stiffening member interposed between the insole and said reinforcing piece, and a second resilient shank stiffening member interposed between said reinforcing piece and theoutsole, said shank stiffening members each comprising an adhesive-producing stiffening medium and being permanently secured directly to'the adjacent parts of the shoe by means of said medium.

10. In a shoe, an insole and an outsole having their shank portions reinforced by means of strips of sheet material impregnated with pyroxylin and interposed between said soles and by a resilient heel and shank reinforcing piece of the full width of the insole interposed between said strips, said strips being anchored by means of said pyroxylin adjacent portions of the shoe.

11. The method of stiffening the shank portion of a shoe which comprises applying a plastic strip 'to become rigid to provide a shank stiffener.

. HARRY C. KING. 

